This book constitutes the refereed proceedings of the 11th International Conference on Computer Aided Verification, CAV’99, held in Trento, Italy in July 1999 as part of FLo C’99.The 34 revised full papers presented were carefully reviewed and selected from a total of 107 submissions. Also included are six invited contributions and five tool presentations. The book is organized in topical sections on processor verification, protocol verification and testing, infinite state spaces, theory of verification, linear temporal logic, modeling of systems, symbolic model checking, theorem proving, automata-theoretic methods, and abstraction.